#include<bits/stdc++.h>
using namespace std;
#define int long long
signed main() {
	int n;
	string s;
	cin >> n >> s;
	for (auto &i : s) {
		for (int j = 1; j <= n; j++) {
			i++;
			if (i > 'z')
				i -= 26;
		}
	}
	cout << s;
	return 0;
}
